Children come running when they hear the ice cream truck's familiar song of summer.
For four years, Debbie Beaver has driven to the same tune every day, 10 hours a day. She falls asleep with the song in her head, and wakes up to it again the next morning.
It's the Mel-O-Dy ice cream truck song, and come rain, snow or shine, children of all ages come running to greet her, Beaver said.
"I've had little kids run out stark naked from a bathtub because they've heard me before Mama did," she said. "Children hear the ice cream tune like dogs hear a dog whistle."
Although summer officially starts Saturday, Beaver said her best business is during spring and fall.
"Pretty much February until now is the busiest time. It slows down when it's real hot," she said.
That smothering heat is almost here.
It was as hot Thursday as it has been all year, 92 degrees.
March 21 and June 12 were the other two days this year to hit the high.
"It's pretty close to normal. Our normal highs are around 89 or 90 degrees, so we're only two degrees above normal," said Dan Spaeth, meteorologist for the National Weather Service.
The heat index for Thursday was 103 degrees. The index uses temperature and humidity to show perceived temperatures.
Spaeth said the heat index "is what it feels like with the moisture content in the air."
"We're running about 10 degrees warmer on the heat index than we would normally expect this time of year," he said.
The dew point, 74 degrees, also is high due to the unusually moist air, he said.
Southerly winds have brought moisture from the Gulf of Mexico, Spaeth said.
Despite the humidity, Tulsa's official rain gauge remains 5.8 inches below normal for the year.
"We haven't had any recent thunderstorms to rain it out," he said.
Friday's high temperatures are expected to be in the lower 90s with mostly sunny skies. Friday night's lows should be in the mid-70s.
Saturday and Sunday, the highs are expected to remain in the 90s with partly cloudy skies, with low temperatures remaining in the 70s.
No rain is expected over the weekend.